The use of screens and filters to remove solid material that is suspended or otherwise part of a fluid stream has been well known. Examples of this can be seen in industry, such as conventional dual basket strainers that are placed in the stream of a chemical to be added to a manufacturing process. The strainers are placed in the stream to assure that solid material, such as dirt from a storage tank, or dried or congealed chemical itself does not reach the manufacturing process, where it could disrupt production. As one strainer fills up or becomes clogged, the flow of the stream is switched to the other. The off line strainer, the one that has clogged, is then removed and cleaned. In this way the flow of the chemical to the manufacturing process is not disrupted.
This example of an apparatus and method of removing solid material from a fluid stream illustrates a problem with prior art filtration and straining devices. These devices fill up with material, which reduces their through put, ultimately plugging and stopping flow. This requires that they be frequently cleaned, which can be an expensive and time consuming process.